Roll grooving tool

ABSTRACT

A tool for rolling external circumferential grooves in pipes by rotation of the pipe between a driven backup roll and a freely rotating grooving roll engaging the outer pipe surface. The grooving roll is mounted in a sliding housing and is urged against the pipe wall by a hydraulic cylinder acting along a line substantially perpendicular to the axis of rotation of the grooving roll. The linear motion of the sliding housing is limited by an adjustable depth stop to produce grooves of uniform depth.

[ Sept. 9, 1975 ROLL GROOVING TOOL 1,816,117 7/1931 2,97 8l9 96l Inventors: Lawrence W. Thau, Jr., Newark; 3 2 502 fl E 5315? I Edward E. Coughlan, Jr., Mercervme both of Primary Examiner-Milton S. Mehr Assignee: Victaulic Company of America, Attorney, Agent, or FirmBrooks Haidt Haffner &

South Plainfield, NJ. Delahunty Flled: June 28, 1974 ABSTRACT Appl. No.: 484,220 A tool for rolling external circumferential grooves in pipes by rotation of the pipe between a driven backup us. 72/105; 72/245 roll and a freely rotating grooving roll engaging the 1m. B211) 17/04 Outer P p Surface The grooving is mounted in a Field of Search 72/101, 121, 124, 105, Sliding housing and is urged Against the p p wall y 72 02 3 l 1 2 109, 94 hydraulic cylinder acting along a line substantially perpendicular to the axis of rotation of the grooving roll. References Cited The linear motion of the sliding housing is limited by UNITED STATES PATENTS an adjustable depth stop to produce grooves of uniform depth. 397,563 2/1889 72/245 1,810,342 6/l93l 72/105 3 m 5 Dr w g lg r United States Patent Thau, Jr. et al.

lllllll IIJIA IIIIIII IIIII IIIII 2m PATENTED H 91975 3. 903 722 SHEETEUfZ TMIL.

ROLL GROOVING TOOL BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the roll grooving of pipe and more particularly to a roll grooving tool having hydraulic means for the controlled application of grooving force.

2. Description of the Prior Art The advantages of piping systems wherein grooved end pipe sections are joined by couplings that interfit with the pipe grooves have resulted in extensive use of grooved end pipe. Various tools are available for cutting grooves in pipe walls, but since cutting a groove substantially reduces the thickness of the pipe wall at the groove, the rolling of grooves is preferable for relatively thin walled pipe.

US. Pat. No. 2,975,819 to Costanzo et al relates to a roll grooving tool in which a screw arrangement is employed to feed a grooving roll inward toward a backup roll as grooving progresses.

Frost et al, US. Pat. No. 3,015,502, shows another roll grooving tool utilizing a screw to bring a grooving roll toward a driven backup roll as a groove is formed, by moving the shaft of the grooving roll. The shafts of the grooving and backup roll have mutually engaged gears.

SUMMARY OF THE INVENTION The roll grooving tool of the present invention provides the advantages of rolled grooves in accordance with the aforesaid US. Pat. No. 3,015,502, the specification of which is hereby incorportated by reference, and also improves the performance of the tool described therein for a wide range of applications.

The tool of the invention has an upright tool body through which there extends a rotatable shaft for connection at the rear of the tool to power drive means. At its forward end, this rotatable shaft carries a backup roll for engaging the inner side of a pipe wall. The backup roll has a radially extending flange fitting between opposed flanges of a grooving roll carried by a freely rotatable shaft. The shaft of the grooving roll is journalled in a housing mounted to slide vertically within the tool body so that the shafts are kept in parallel alignment while the vertical spacing between the shafts and the rolls carried thereby is changed. A single acting hydraulic cylinder connected to a source of hydraulic fluid under pressure serves to force the housing of the grooving roll down to press the grooving roll against the outer surface of a pipe supported by the backup roll as the pipe rotates to form a circumferential groove therein.

The hydraulic cylinder is vertically oriented to exert its force on a line perpendicular to and intersecting the axis of rotation of the grooving roll. A rod extending from the top of the cylinder moves downward with the motion of the sliding housing and the abutment of stop means adjustably mounted on this rod with the top of the cylinder stops further motion of the grooving roll towards the backup roll at the desired groove depth.

The hydraulic cylinder can be supplied with hydraulic fluid under pressure by means of a hand pump which can be operated by the operator of the tool so one man can groove pipes very effectively. By providing a pressure relief valve for the hydraulic system, a substantially constant high level of force can be employed without danger of overloading the tool. This pressure relief also accommodates uneveness in the wall of a pipe being grooved.

A spring return arrangement brings the grooving roll housing back to its upper, inoperative position when the pressure ceases, so that a grooved pipe can be readily removed and a new pipe inserted for grooving.

These and other features and advantages of the tool of the invention will be more fully understood from the following detailed description of a preferred embodiment, especially when that description is read with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a view in side elevation ofa tool according to the invention.

FIG. 2 is a top plan view of the tool of FIG. 1.

FIG. 3 is a view in section of the tool of FIGS. 1 and 2 taken along line AA of FIG. 2 and looking in the direction of the arrows.

FIG. 4 is a view in section of the tool of FIG. 1 taken along line BB of FIG. 1 and looking in the direction of the arrows.

FIG. 5 is a front view in elevation of the tool of the tool of FIGS. 1 4, with dashed lines showing certain hidden parts.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT The roll grooving tool of the invention as shown in the several figures of the drawing has a strong tool body, generally indicated by reference numeral 1. This tool body is preferably integrally formed as an aluminum casting for combined light weight and strength. A housing generally designated 2 is mounted for vertical sliding movement within the tool body 1. As best seen in FIGS. 2, 3 and 4, the tool body I has a block-like base portion 3 and a pair of spaced parallel arm portions 4 extending upward and forward from opposite sides of the base portion 3. At the front of the tool the upper ends of the arm portions 4 are joined by a vertically extending face portion 5 of the tool body 1 as best shown in FIG. 5.

The tool body 1 thus has an open space defined between its arm portions 4 within which space the housing 2 is slidably mounted. As shown in the top view of FIG. 3, the housing 2 is stepped inwardly to form a pair of outwardly open generally rectangular channels 6 that extend vertically at the rear of the housing 2. These channels slidably engage vertical slide rail members 7, 9 and 11 to permit only vertical motion of the housing 2 between the arms 4 of the tool body 1. As shown in FIG. 4 the slide rail members 7 and 9 are each secured to their respective arms 4 by a plurality of screws 8. Although each side of the housing 2 could be guided by a slide rail like the rail member 7, it has been found to be advantageous to make the vertical guide arrangement adjustable by employing a pair of outer and inner slide rail members 9, 11 at one side of the tool. The total width of the combination of rail members 9 and 11 is equal to that of the rail member 7, but this width can be adjusted by means of a pair of set screws 12 extending through the outer rail member 9 to the inner rail member 11. Access holes for adjusting these screws are shown in FIGS. 1 and 4. The inner slide rail is secured in position parallel to the outer slide rail member 9 by a pair of dowels 10. At the rear of the housing 2 a rectangular plate 14 secured to the housing 2 constitutes the back wall of the channels 5.

A sturdy plate 39 is mounted atop the arms 4 at the front of the tool body 1 above the housing 2 by means of screws 41 as shown in FIGS. 2, 3 and 5. A single acting hydraulic cylinder generally indicated by reference numeral 53 is mounted on and extends through the plate 39. The piston 54 of the cylinder 53 is secured to a cup-shaped connecting member 37, the base 55 of which is received within a well 56 formed in the top of the housing 2 and fastened to the housing 2 by a screw 36 as shown in FIG. 3. The cylinder 53 is of a commercially available type having an axial rod 38 fastened to and extending through the piston 54 for movement therewith. At its lower end the rod 38 is fastened by a pin 35 to the connecting member 37. The threaded upper end 57 of the axial rod 38 is seen in FIG. 3 to extend vertically above the cylinder 53 through a cup-like depth stop 40 that is threaded on the upper threaded portion 57 of the rod 38, vertically adjustable on the rod 38 and held in its adjusted position by means of a lock nut 72. A spacing plate element 43 can be mounted atop the housing 2 as shown in FIGS. 1, 3 and 5.

The several drawing figures show the cylinder 53 with its piston 54 fully extended, so that the depth stop 40 is in contact with the top of the cylinder 53. It will be understood that retraction of the piston 54 will cause the rod 38 to move upward. carrying the depth stop 40 out of contact with the cylinder 53. By adjusting the depth stop 40 on the threaded upper end 57 of the rod 38, a limit is set for the extent of downward movement of the piston 54 and the housing 2. A powerful return spring 58 encircles the upper end 57 of the rod 38 to aid in retraction of the piston 54 when hydraulic pressure is cut off.

Since, as indicated. the cylinder 53 is of a commercially available type, the structural details of the cylinder will not be discussed. In the preferred embodiment of the tool of the invention the cylinder should be capable of exerting a vertical force of 10,000 pounds, which is highly effective for rolling a groove in a pipe wall.

The housing 2 has a downwardly open recess 61 for the grooving roll 60, which is mounted on a shaft 33 journalled at its ends in the housing 2. Because of the heavy load imposed on the shaft 33 in operation of the tool, durable needle bearings are employed at the shaft ends as shown at and 34 in FIG. 3. A ball thrust bearing 16 for the shaft 33 is press fitted in a bearing retainer 18 secured to the back plate 14 by means of a screw 17. Adjustability in the axial direction is pro vided by an Allen set screw 20 and a hexagonal nut 19 as shown in FIG. 3. This permits precise axial positioning of the grooving roll 60. The shaft 33 is not driven. and unlike the shaft of the grooving roll in the aforementioned U.S. Pat. No. 3,015,502, the shaft 33 is accurately maintained in a horizontal attitude.

The driving force for rotation of a pipe during grooving is carried by a main shaft 28 extending through the base portion 3 of the tool body 1 as shown in FIGS. 3 and 4. Near its front end 28A the shaft 28 is conic-ally tapered to fit within the similarly conical axial opening through the backup roll 62. A large castellated nut 50 and lock washer on the threaded cylindrical end 288 of the shaft 28 serve to retain the backup roll 62 on the shaft 28. The roll 62 is keyed to the shaft 28 as shown at 29 in FIG. 3.

At the rear of the tool body 1 the shaft 28 is keyed as shown at 23 to a shaft adapter member 51 for connection to power drive means. A l-inch square connec tion suitable for power mule, flexible drive or other power drive connection is employed. The maximum output of the power drive for the tool of the invention should be about 1.5 horsepower, at a main shaft speed no greater than about 40 RPM.

As in the case of the shaft 33, needle bearings shown at 27 and 52 are employed at the forward end of the shaft 28. The minimum distance between the shafts 28 and 33 can be quite small, as shown, because of the space saved by using needle bearings. lf the shafts were spaced farther apart, the grooving roll and the backup roll 62 would, of course, have to be larger.

At the rear of the tool base 3 a double opposed Timken tapered roller bearing 25 restrains the shaft 28 axially, and absorbs axial loading on the shaft 28. To the rear of the bearing 25, a Timken combination nut and dust collar 24 encircles the shaft 28, as shown in FIG.

The opposed rolls 60 and 62 have a grooving flange 63 and a contoured groove 64 respectively in accordance with the teachings of US. Pat. No. 3,015,502 for rolling into a pipe wall a groove that is optimally shaped for the reception of the key section of an external coupling housing. A radially extending tongue flange 65 of the backup roll 62 fits within a slightly larger radial groove 66 of the grooving roll 60 for mating alignment of the rolls 60 and 62. in the aforesaid US. Pat. No. 3,015,502, the reverse of this arrangement was disclosed. However, it has been found that the placement of the tongue flange on the driven backup roll not only reduces the axial length of the rolls, but also brings the line of action of the main grooving force nearer to the front main bearing 27 of the shaft 28 and thereby reduces the stress on the shaft 28.

The spacing plate element 43 is employed when rela tively small rolls 60, 62 are used. This plate limits upward motion and relative separation of the shafts 28 and 33 to prevent disengagement of the rolls 60, 62. The tongue flange 65 is thus kept within the groove 66 even when small rolls are in their extreme open position.

To assist in the driving of a pipe by the backup roll 62. the pipe engaging surface of the roll 62 is knurled for better driving contact.

It has been noted that the grooving roll shaft 33 is axially adjustable by means of the adjustable thrust bearing 16. The single flange 65 of the backup roll 62 is slightly tapered as shown in FIG. 3. This flange acts as the end stop against which the end of a pipe is thrust for engagement of its wall between the grooving flange 63 and the backup roll 62, and this advantageous tapered surface could result in axial displacement so oc casional axial adjustment is advisable to keep the rolls exactly centered for best grooving operation.

The grooving roll 60 is keyed to the shaft 33 for rotation therewith by means of a pair of set screws 49 fitted in radial holes through the grooving roll 60 as shown in FIGS. 1 and 3. These set screws are of such length that unless the roll 60 is in its proper position the position of the screw heads will indicate inaccurate roll location.

As shown throughout the drawings, provision has been made for easy lubrication of all moving parts.

The tool body 1 and slidable housing 2 are subjected to great loads during grooving. Because of this the di mensions of the tool parts should be chosen with a view to strain rather than the usual stress considerations. In this way elastic deformation of the castings themselves under the maximum grooving force of 10,000 pounds can be minimized to ensure uniform grooving operation.

The operation of the tool is simple. Because its larger parts are of aluminum. the tool is portable. Feet 70 of the tool as shown best in FIGS. 2 and 5 are firmly secured to a sturdy platform, bench or table, with the tool in a level position. A quick-disconnect hose connector 71 shown in FIG. 1 is provided for connection of the cylinder 53 to a hydraulic line. A commercially available hydraulic hand pump having a pressure relief valve is employed to prevent overloading of the tool through the relief of pressure at any pressure higher than that needed for the application of the proper grooving force.

Since the rolls 60 and 62 always return to the open position when hydraulic pressure is not acting on the cylinder 53, the end of a pipe can be slid over the backup roll 62 until it touches the flange 66 which acts as an end stop. The pressure relief valve of the hydraulic pump is then closed to apply pressure. The pump should be of the type having a handle which can be grasped by the operator with one hand while he supports the pipe with his other hand. Of course, if a long pipe section is being grooved, some support structure. such as a V-rest roller pipe stand can hold the pipe.

Pumping the handle several times brings the grooving roll 60 into firm contact with the outside of the pipe. Then power is applied to rotate the pipe and proper tracking of the pipe is checked. The operator can assist the tracking action by moving the pipe end that is not in the tool slightly (about one-half degree). Referring to FIG. 5 showing the front face of the tool, if the pipe is rotating clockwise to an operator facing the tool, the pipe should be moved to the left of center about onehalf degree. In case of counterclockwise rotation the pipe should be moved to the right to the same extent. If a pipe rest is employed it should be similarly positioned slightly off-center. This small angle helps the pipe to track properly and holds the pipe against the flange 66.

To begin grooving the rotating pipe, the pump handle is pumped while the pipe continues to rotate. Since all of the grooving force is applied by the hydraulic cylinder 53 controlled by the pressure relief valve of the pump. the proper amount of force is semiautomatically applied.

Grooving continues with gradual application of force by pumping until the desired groove depth is reached. The depth stop 40 regulates groove depth. This depth stop 40 can be adjusted for each pipe size or wall thickness.

To adjust the depth stop 40, the lock nut 72 is backed off and a pipe is inserted between the rolls 60 and 62 and some pumping is done to tightly engage the pipe. Then the stop 40 is screwed up to a point at which the distance between the bottom of the stop 40 and the top of the cylinder 53 equals the desired groove depth. A gauge such as a small piece of metal can be used to check this distance. A trial groove is then made and measured, and if further adjustment is required the stop 40 can be moved closer to or further from the cylinder 53.

The pipe to be grooved should have a square cut" end on a smooth plane perpendicular to the pipe axis. The pipe end should be clean and relatively smooth for good grooving. The tool is particularly well suited to grooving pipe of steel, stainless steel and aluminum, though other types of metal pipe can also be grooved with the tool of the invention. Pipe to be grooved by rolling usually ranges from about 2 inches to 16 inches in diameter with a wall thickness from about 0.065 to 0.280 inches. The grooves to be formed generally correspond to the teachings of US. Pat. No. 3,015,502.

The rolls and 62 can be removed and replaced with rolls having other dimensions if different groove dimensions are desired.

Although a particularly preferred embodiment of the tool of the invention has been described in detail, certain modifications and other applications will be obvious to those acquainted with the art of pipe grooving. For example, two tools in tandem could groove opposite ends of the same pipe simultaneously. The tool could be provided with a self-contained drive if desired. Total automatic operation including control of groove depth can be provided in certain applications. These and other obvious modifications and applications are considered to be within the spirit and scope of the invention.

What is claimed is:

l. A tool for roll grooving of pipe comprising a grooving roll and a backup roll, a first shaft carrying said grooving roll and a second shaft carrying said backup roll, means for maintaining said shafts in spaced parallel relationship. fluid actuated means for moving one of said shafts toward the other of said shafts in a plane defined by the axes of said shafts, and adjustable stop means associated with said fluid actuated means for limiting the movement of said one shaft toward the other to provide a groove of predetermined depth.

2. The tool of claim I wherein said second shaft is mounted for rotation about a fixed axis and said first shaft is journalled in a housing mounted for vertical sliding movement. and wherein said fluid actuated means comprises a hydraulic cylinder having a piston secured to said housing.

3. The tool of claim 1 wherein the fluid actuated means comprises a hydraulic cylinder mounted to exert force along a line passing through the centerlines of both said rolls.

4. The tool of claim 1 wherein said second shaft is arranged to be driven and said first shaft is freely rotatable.

5. The tool of claim 1 wherein said grooving roll has a circumferential recess and said backup roll has a radially extending tongue flange received within said recess during grooving operation.

6. A tool for roll grooving of pipe comprising a tool body and a housing mounted for vertical sliding motion within said body, a hydraulic cylinder mounted on said tool body for moving said housing therewithin, said hydraulic cylinder having a piston secured to said housing and an axial rod fastened to said piston for movement therewith, a portion of said rod extending through a top of said cylinder carrying a vertically adjustable depth stop member for stopping downward movement of said housing by engaging said cylinder top, and a grooving roll mounted on a shaft joumalled in said housing and 7 a backup roll mounted on a shaft journalled in said tool body.

7. The tool of claim 6 wherein said shafts are parallel and wherein said hydraulic cylinder exerts force along a line passing through the centerlines of said rolls.

8. The tool of claim 6 wherein spring means associated with said hydraulic cylinder returns said housing to an upper position when said cylinder is not under pressure.

9. A tool according to claim 6 and including bearing means for preventing axial movement of said shafts.

10. A tool for roll grooving of pipe comprising a tool body and a driven shaft extending horizontally through said body, a backup roil keyed to said driven shaft, a grooving roll in opposed relationship to said backup roll. said grooving roll being carried by a freely rotatable shaft journalled in a housing mounted to slide vertically within said tool body, means to maintain said shafts in parallel alignment while the vertical space between said shafts is changed and a single acting hyraulic cylinder mounted on said tool body for forcing said housing downward, a rod extending from the top of said hydraulic cylinder being mounted to move downward with the motion of said housing, and stop means adjustably secured on said rod limiting the extent of downward movement.

cylinder for limiting the pressure acting thereon. 

1. A tool for roll grooving of pipe comprising a grooving roll and a backup roll, a first shaft carrying said grooving roll and a second shaft carrying said backup roll, means for maintaining said shafts in spaced parallel relationship, fluid actuated means for moving one of said shafts toward the other of said shafts in a plane defined by the axes of said shafts, and adjustable stop means associated with said fluid actuated means for limiting the movement of said one shaft toward tHe other to provide a groove of predetermined depth.
 2. The tool of claim 1 wherein said second shaft is mounted for rotation about a fixed axis and said first shaft is journalled in a housing mounted for vertical sliding movement, and wherein said fluid actuated means comprises a hydraulic cylinder having a piston secured to said housing.
 3. The tool of claim 1 wherein the fluid actuated means comprises a hydraulic cylinder mounted to exert force along a line passing through the centerlines of both said rolls.
 4. The tool of claim 1 wherein said second shaft is arranged to be driven and said first shaft is freely rotatable.
 5. The tool of claim 1 wherein said grooving roll has a circumferential recess and said backup roll has a radially extending tongue flange received within said recess during grooving operation.
 6. A tool for roll grooving of pipe comprising a tool body and a housing mounted for vertical sliding motion within said body, a hydraulic cylinder mounted on said tool body for moving said housing therewithin, said hydraulic cylinder having a piston secured to said housing and an axial rod fastened to said piston for movement therewith, a portion of said rod extending through a top of said cylinder carrying a vertically adjustable depth stop member for stopping downward movement of said housing by engaging said cylinder top, and a grooving roll mounted on a shaft journalled in said housing and a backup roll mounted on a shaft journalled in said tool body.
 7. The tool of claim 6 wherein said shafts are parallel and wherein said hydraulic cylinder exerts force along a line passing through the centerlines of said rolls.
 8. The tool of claim 6 wherein spring means associated with said hydraulic cylinder returns said housing to an upper position when said cylinder is not under pressure.
 9. A tool according to claim 6 and including bearing means for preventing axial movement of said shafts.
 10. A tool for roll grooving of pipe comprising a tool body and a driven shaft extending horizontally through said body, a backup roll keyed to said driven shaft, a grooving roll in opposed relationship to said backup roll, said grooving roll being carried by a freely rotatable shaft journalled in a housing mounted to slide vertically within said tool body, means to maintain said shafts in parallel alignment while the vertical space between said shafts is changed and a single acting hyraulic cylinder mounted on said tool body for forcing said housing downward, a rod extending from the top of said hydraulic cylinder being mounted to move downward with the motion of said housing, and stop means adjustably secured on said rod limiting the extent of downward movement.
 11. The tool of claim 10 wherein said hydraulic cylinder is vertically oriented to exert force along a line perpendicular to and intersecting the axis of rotation of the grooving roll.
 12. A tool according to claim 10 and including a spring return means for bringing said housing to an upper, inoperative position when pressure on said hydraulic cylinder is relieved.
 13. A tool according to claim 10 and including pressure relief valve means associated with said hydraulic cylinder for limiting the pressure acting thereon. 